package com.lxq.test1709.main01;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int money = sc.nextInt();
        int count=0;

        count = money/10;
        count = count + count/5*2 + (count%5)/3*1;

        System.out.println(count);

    }
}
